Betelgeuse, a dying red star

Saturday, January 29, 2011

By DAVID WARGO don'tblink2003@hotmail.com

Luke Skywalker stands on the desert of Tantooine near his Aunt Beru and Uncle Owen's home observing the setting double sun setting and longing for action and adventure. This is one of the early scenes in the epic film "Star Wars", but it may not be science fiction in our future at least for a few weeks. Betelgeuse is a dying red supergiant star in the Orion constellation about 640 light-years away from here.

The star is enormous. Some estimates I have found place the size of this star as large as the orbit of Jupiter from the Sun. Not the planet Jupiter, but the elliptical orbit it makes around the Sun. This is a distance of 460,171,000 miles at its closest. That means that Betelgeuse normally has a diameter of 920,342,000 miles. It is hard to conceive such distances, but to compare it to something relative we are talking about a circumference of over 2.8 trillion miles. That distance is 116,114 trips around the Earth at its equator, a trip that would take approximately 824 years to complete at a constant continual speed of 200 miles per hour.

Unfortunately, Betelgeuse is heading for the end of its days according to scientists and when that occurs, which could be as early as the next year or so or as late as the next million years, we will have a front-row seat for the event relatively speaking. Even though the star is humongous by our solar system, it is located in the Orion constellation which is far enough away to protect us from a cataclysmic effect from this dramatic event, but close enough that it will affect the solar system at least visually.

Scientists in an article on the website Daily Mail, a United Kingdom news site report that the effect of Betelgeuse's supernova would be to cancel out night on earth for weeks turning what should be night time into a month long continual day. We would see two suns in the sky at this time for this brief period mirroring the previously mentioned scene in Star Wars. Or would we?

Betelgeuse is currently a pinhead in the night sky. If it explodes at that distance it would probably become quite bright for a few weeks, but it would not grow to the size of the sun. Other scientists say it would be brighter than a full moon and it may bother the eyes to look directly at it. It could affect the night sky for a few weeks, but dissenters believe it would look nothing like a second sun, so don't go buying sunglasses just yet.

While scientists say the explosion could occur within the next year or so, they have not narrowed down the window. Like weathermen, their prediction is as large as a barn door estimated anywhere from next week to a million years from now. One commenter on the news story pointed out that even if Betelgeuse exploded tomorrow we wouldn't see it for a million years. Not quite so.

Many of you may know this but for those that do not, distance in space is measured either in astronomical units or light years. An astronomical unit is the distance of our earth to our sun, about 93 million miles. A light-year is the distance a particle of light travels in one year at 186,000 miles per second making this distance. It is estimated Betelgeuse is 640 light years away which means the light we see today originated there 640 years ago, so if the star exploded 640 years ago, we would see it today. The catch is we have no way of knowing when the star would explode so if it literally exploded today, no one on this planet would see the light from it until 2651.

It would be definitely a once in a lifetime spectacle to see from our planet, but it will not affect our world per se. Of course not everyone would have you believe this. The same article intimates that one of the 2012 doomsday scenarios which have been circulating at light speed for the past few years involves the explosion and subsequent cataclysmic effects on the this planet from this supergiant.

Not so. In order for Betelgeuse to affect us it would have to be within 25 light years of this planet. It is currently 25. 6 times farther away. We will be bombarded with neutrinos which are harmless quantum particles that will be generated by the blast, but this will not affect us either. In short, the explosion will simply be one of those once in a lifetime visual effects that will be impressive but not at all dangerous to us.

When it does complete its explosion, Betelgeuse will compress and fade into the night sky and into the annals of astronomical history, but we will still be here. Contrary to popular belief, the explosion of this star even if it occurs in the next two years does not signal the end of our world, just an extremely cool experience that everyone should observe.